First, I appreciated the thoughtful responses I received to my previous post. To those of you who referred me to the avweb and other articles, thank you. I read them, and was just about convinced, until I went back and looked at a Continental bulletin, Sid 97-2, dated 2-17-97. Let me quote:
"The highest combustion temperatures occur near the ideal fuel/air ratio of about one pound of fuel for 15 pounds of air. Combustion temperatures drop on both the lean side and rich side of this point. However,on the lean side of peak the reduction in power with leaning is rapid and lean misfire occurs on many engines about 100 degrees lean of peak. On the rich side power is very stable with changes in fuel flow. This characteristic allows the engine to obtain rated power with rich mixtures where the combustion temperatures are substantially reduced. This additional fuel at takeoff is required to maintain control of cylinder structure and oil cooling.
In cruise, operating rich reduces combustion temperatures and should be used to control engine temperatures. For maximum range, operation on the lean side of peak or at peak is permitted at low cruise power on some engine models. For normal operation, it is good practice that mixtures be controlled so that the hot cylinder is 50 to 100 degrees rich of peak at cruise settings . . . "
So, here I sit, absent engine monitor and confused as ever. Who’s a poor middle-aged midwesterner to believe, mechanics, the articles, or the technical bulletin of the engine manufacturer.
Which opinion do you find most reliable, and how are those of you with IO-360s currently operating them?